Incidence, prevalence and severity of fall armyworm infestation in Ghana: a case of two maize enclaves in the Ashanti Region of Ghana

Maize production is an important enterprise in Ghana, providing livelihood for thousands of people. It is challenged by fall armyworm infestation causing destruction to many cultivated lands in production enclaves and threatening food security. Effective control, however, requires information on the actual pest infestation as well as the effect of climate factors on infestation in these enclaves. The study assessed the incidence, prevalence and severity of fall armyworm infestation on maize farms in two major maize enclaves (Ejura and Ejisu) in Ghana. Data was taken on the presence, infestation levels and damage of fall armyworms as well as the climatic conditions in each district. Data collection was done by sampling 50 maize plants each on 40 maize farms in both districts and assessing them for the incidence, larval prevalence, leaf damage and severity. Results showed varying infestation in both districts (p < 0.0001) with Ejisu having a higher prevalence (0.10 +/- 0.04 larvae per plant) than Ejura (0.05 +/- 0.03 larvae per plant) in the minor season at seedling stage. At the vegetative stage, Ejisu recorded a higher prevalence in both seasons. A low severity was recorded at the seedling stage in both districts for all seasons which, however, varied among seasons at vegetative stage. Climatic variables including rainfall, temperature, relative humidity and wind were found to significantly impact infestation in both districts. The study thus, showed fall armyworm infestation to be a major challenge to maize production in both districts confirming it as a major constraint to maize production in the region.